Conventionally, an electrographic image forming device for forming an image using an LED head where a plurality of light emitting diodes (LEDs) are arrayed in an approximately linear arrangement, and a reading device, such as a scanner, a facsimile and the like, for forming an image of a manuscript on a light receiving part where a plurality of light receiving elements are arrayed in an approximately linear arrangement are known. In these devices, as an optical system for linearly forming an equal magnification erect image of an object, a lens array where a plurality of micro-lenses are arrayed in an approximately linear arrangement is used (for example, JP Laid-Open Patent Application No. 2009-86649 (see FIG. 5)).
Although the lens array such as described above is generally formed by injection molding, it is known that flow marks are generated at the time of injection molding, reducing lens array resolution. Consequently, when a lens array is used in an optical system of an imaging forming device, there is a problem that stripes and/or density unevenness is generated on a printed image. In addition, when the lens array used for an optical system of a reading device, there is a problem that the image data of a manuscript cannot be accurately taken in.
In view of the problems above, the objective of the present application is to prevent the reduction of the lens array resolution caused by flow marks at the time of molding.